Belt press to dewater sludge
Solid waste, commonly called sludge, comprises of approximately 1.5% solids and 98.5% liquid by the time the biological processing is complete.
Proper handling of sludge is a very important and the mission of wastewater treatment plant (WWTP) municipality plant is to separate solids from water, and to disinfect both to different degrees by removing organic and inorganic contaminants, which may be hazardous or toxic to humans or have detrimental effects on the environment. The main key element in the wastewater treatment process is the Belt Press, which is used to dewater the sludge and change it from a liquid to a solid.
West Virginia’s City of Nitro Waste Treatment Plant (NWTP) brings out a superior solution to their existing Belt Press. With previous experience using OR-TEC’s Screw Screens successfully for a number of years at the inlet of their plant to remove non organic debris (plastics, rags, sticks etc.), Danny Lewis, NWTP’s Plant Superintendent, invited OR-TEC to bid on their new system.
At 2.2 metres wide, the Gemini Series Belt Press is the largest made by OR-TEC and is ideal for the medium to large size WWTP. This press combines a gravity drainage zone, a squeezing zone, and high pressure shear zone to provide a large dry solids throughput of up to 1,500 lbs. per hour.
The unit has a large flocculation tank with a variable speed mixer which allows the sludge and polymer solution to be thoroughly mixed. Following the flocculation tank, the sludge enters a large gravity zone where dewatering rollers begin the process of thickening the sludge. From here, the thickened sludge enters a low pressure zone which features a large perforated stainless steel roller followed by an increasing pressure wedge zone. The final dewatering zone is a high pressure area where multiple rollers of decreasing diameter continue to squeeze and dewater the sludge.
A single control panel is used for all this equipment, and the Belt Press system also features electric actuation so no hydraulics or pneumatics are needed. OR-TEC advised and supplied all aspects of Nitro’s system, adding value via working out all of the kinks at every stage of implementation.
Delivered in September 2016, Nitro’s new Belt Press system has now been in operation for months and running at advanced capacity and performance. According to NWTP’s Danny Lewis, “The system handles a lot of throughput, so there is substantially less for operators to deal with on a daily basis. There’s no oil, filters, or air supply needed so it’s more user friendly, easier to operate, and maintain.”